make a NICE laptop, which is fully upgradeable and suitable for Gaming. Rivals Alienware, cheaper, with better service and warranty options, IMO.
Spending $4000 on a Sager Notebook will leave you a VERY happy customer.
That said ... I just cannot justify the price of a performance/gaming laptop over a desktop. For $4000, I could build (or purchase) a custom system that looked great, out-performed anything on the market, ran cool AND quiet, and had dual 24 Inch Hi-Res LCD's, or 32 Inch Low res (1280/1366) OR one large 37 - 42 in display ...
Although why anyone would want two crappy 1366x ... LCD's for gaming is beyond me.